Electrical hair-erector shaver



May 2, 1967 R. TAPPER 3,316,633

ELECTRICAL HAIR-ERECTOR SHAVER Filed Oct. 14, 1965 FIG. 6.

I J M94 F I G. 7.

1N VEN TOR.

-12 ROBERT TAPPER BY f 83 Q .m/

AGENT United States Patent Office 3,316,633 Patented May 2, 1967 ELECTRICAL HAIR-ERECTOR SHAVER Robert Tapper, General Medical Co., 5701 W. Adams Blvd., Los Angeles, Calif. 90016 Filed Oct. 14, 1965, Ser. No. 496,101 9 Claims. (Cl. 30--34.2)

This invention pertains to means for obtaining an improved shave and more specifically to erect hairs by electro-rnuscular stimulation.

In general, man has long sought a close shave. With modern electric (electro-mechanical) shavers, means to quickly shave off certain hairs of a beard that lie along the surface of the skin is also desired.

Fortunately, each hair that man seeks to shave off is provided with a muscle, the arrector pili, and this muscle can be excited by electric current. Such excitation makes the hairs stand on end; i.e., to erect perpendicular to the skin, thus to be most effectively shaved off by the shaver device.

For the physiology concerning the a-rrector pili, reference is made to the text, The Hair and Scalp, A. Savill and C. Warren, th ed., The Williams & Wilkins Co., Baltimore, 1962, pages 9-10. For the mechanism of exciting muscles by electricity, reference is made to the text, Medical Electronics, E. Bukstein, Frederick Ungar Publishing Co., New York, 1959 (Library of Congress No. 599l47), pages 135-37.

In the present invention, an electrode disposed adacent to the means for cutting hair is supplied with successive alternating current (A.C.) or direct current (DC) pulses to erect the hairs just prior to shaving the same. A return electrode is disposed farther away from the means for cutting hair than is the first-mentioned elect-rode. The return electrode may have the same or larger area than does the first-mentioned electrode, typically, in contact with the skin of the person who is shaving.

The objects of this invention include providing:

Means for improving shaving performed with mechanical clipping apparatus,

Means to erect hairs to be removed by electrical stimulation of the arrector pili muscles thereof.

Electrodes disposed in relation to the cutter head to effect erection of hair, and

Electrical means for energizing the said electrodes disposed in relation to the cutter head.

Other objects will be apparent upon examining the following specification and drawings, in which are set forth by way of example certain embodiments of the invention.

FIG. 1 shows a plan view of a multiple-head razor having electrodes according to this invention,

FIG. 2 shows a half-wave rectifier embodiment of an electrical energizing circuit,

FIG. 3 shows an alternate embodiment of an electrical energizing circuit which employs a direct current supply source,

FIG. 4 shows a plan view of a single-head razor having electrodes,

FIG. 5 shows a side elevation of an alternate arrangement of electrodes,

FIG. 6 shows a full-wave rectifier embodiment of an electrical energizing circuit, and

FIG. 7 shows an alternating current embodiment of an electrical energizing circuit.

In FIG. 1, numerals 1, 2, and 3 indicate typical identical shaving heads of a known type; such as those having stationary transverse teeth on the upper surface thereof and rcciprocable mating teeth below that surface, which are driven by a motor and crank or an equivalent prime mover. Interspersed between these heads are rollers (electrodes) 4, 5, 6, and 7. These have pin end shafts journaled in an insulated end mount, which forms a part of the body of the electric razor. The rollers are cylindrical and thus provide a contact of limited area between each roller and the face of the person shaving. This provides muscle-activating electrodes of relatively small area, thus having increased current density adjacent to the means for cutting hair. It will be understood that when the razor head is lightly pressed against the face only a narrow line of contact is established between each of the rollers (electrodes) and the face. Even when the razor head is heavily pressed against the face the area of contact is only a small fraction of the diameter of each of the rollers (electrodes).

Shaving heads 1, 2, and 3 have a larger area and may be used as current-return electrodes. The presence of such electrodes does not de-energize the hair muscle. The arrector pili are stimulated by electric current, but relax in a time interval dependent upon physiological and not electrical factors.

FIG. 2 shows an'electrical energizing circuit for the head structure of FIG. 1.. Electrical connections from one figure to the other are made by conductively joining the pair of x, x points of each. In FIG. 1 each of rollers (electrodes) 4, 5, 6 and 7 are shown electrically connected together and to the right-hand terminal x. In this way the rollers become electrodes.

Numeral 10 indicates a usual source of alternating current. This may have any frequency commonly available, as 25 to 60 cycles per second, and a usual voltage, as volts. In practice this can be obtained by plugging into the known wall electric outlet. A voltage stepdown transformer 11 has primary 12 connected to the outlet. (A switch for on-off operation may be interposed in series, if desired, or the plug of an electric cord merely pulled out of the wall outlet to accomplish the same purpose.) Secondary 14 has fewer turns than does primary 12, to give a R.M.S. voltage within the range of from 1.5 to 3.5 volts. This gives a peak value of from approximately 2 to 5 volts. The current required is small; of the order of from 0.5 to 1.5 millianiperes. Thus, the transformer may be very small and inexpensive, having a total volume, say, of less than one cubic inch.

One way in which muscle-energizing electric current is effective is when it has the form of relatively rapidly repeated unidirectional pulses with slight separation in time between each pulse; which can be provided by halfwave rectification of alternating current. Such rectification is provided by rectifier 15 in FIG. 2, which may be of the simple and inexpensive semiconductor diode variety.

The cathode 16 connects to one terminal of secondary 1 4-, while the second terminal of that secondary connects to activating rollers (electrodes) 4 through 7. This gives a negative polarity to these electrodes, as is desired in this embodiment. Anode 17 of the rectifier connects to current return electrodes 1 through 3 and impresses upon them a positive polarity.

For battery operation, electrical means according to the circuit of FIG. 3 may be used. Battery 20 may have a voltage of the order of 2 to 5 volts, it may be small so that the device may be self-contained, and the negative terminal of the battery is preferably connected to activating rollers (electrodes) 4 through 7 in FIG. 1 through the x points at the right of these figures. The positive terminal of the battery connects to a buzzer device 21, which has coil 22, paramagnetic core 23, pivoted springretu-rn paramagnetic arm 28, and stationary contact 24. The second terminal of coil 22 is electrically connected to arm 28. Contact 24 connects to return electrodes 1 through 3 via the left-hand x points.

In operation, device 21 initially conducts current, since arm 28 is spring-biased to make electrical contact with stationary contact 24. However, as soon as the current builds up to a nominal value, the magnetic flux produced in core 23 by the current flow in coil 22 attracts arm 28 and thereby breaks contact between the arm and contact 24. This causes the current in coil 22 to cease. With the combined effects of electrical inertia due to the inductance of coil 22. and the mechanical inertia of arm 24, the current passes for a time and then is interrupted for a time, giving the current pulses sought. An additional spring support for the contact on arm 28 may be added, if desired. It will be recognized that should the axis for the current be considered as placed half way between zero and maxim-um amplitude, a form of alternating current has been produced. An intermittent or alternating current is required for the muscle stimulation sought.

The impedance of the human flesh between electrodes 1-3 and 4-7 is high; of the order of 12,000 ohms. This is not sufficient conductivity to operate device 21. Therefore, shunt resistor 25, having a resistance of the order of 30 ohms, is connected across the rest of the circuit, as at the x points. A simple switch 26, of the type that remains open or closed according to appropriate manual manipulation, is provided between contact 24 and resistor 25. This allows the device to be turned on and off at will, thus saving the battery when the device is not in use. It will be appreciated that should the battery and switch of a cordless (battery operated) electric shaver provide the proper voltage and circuit these elements may serve as illustrated elements 20 and 26.

An alternate arrangement of the activating and the return electrodes on a shaver head is shown in FIG. 4. This arrangement is particularly suited to a single head type razor, but may be used with any type. Typically, a narrow and stationary activating electrode 30 is provided within the working area of the head 31, in a central position as shown. It is possible for electrode 30 to be less long than as shown. Preferably two return electrodes 32 and 33 are located on each side of head 31, and upon the same plane, so that these electrodes are in contact with the skin when shaving is taking place. Electrode 30 is insulated from shaver head 31, since the latter is almost invariably of metal. Electrodes 32 and 33 have semicircular cut-out portions opposite activating electrode 30 so that there will not be a shorting (too low impedance) of the electrical effect through the part of the flesh there located and a consequent lack of the required electric current effect upon the muscles over the remaining part of the head of the razor, as is desired.

Electrical conductors 34 and 35 connect return electrodes 32 and 33 to the left-hand x point and conductor 36 connects activating electrode 30 to the right-hand x point. These x points may be connected to correspond ing points in FIGS. 2, 3, 6, or 7 for electrical excitation.

FIG. shows an alternate arrangement of electrodes in which the activating electrode comprises one or more shaver heads, such as the single type 40 illustrated. The return connection is made through the hand of the operator, via a metallic plate or insert on the side of the razor, this being return electrode 41. A similar electrode can be placed on the opposite side of the razor to provide certain hand contact regardless of the grip taken by the operator. Both return electrodes are electrically connected together. The main body of the razor 42 is of insulative material, such as a molded plastic, so that there shall be insulation between head 40 and return electrode 41.

A further alternate electrical means for exciting the electrodes is shown in FIG. 6. This is a full-wave rectified circuit. It follows FIG. 2, but with a center-tapped low voltage secondary 44. The opposite extremities of this secondary connect to the cathodes of rectifiers 45 and 46 and thence to the positive output terminal of this electrical supply via the anodes. The center tap of the secondary connects to the negative output terminal. Twice as many pulses are provided per second with this circuit as with the half-wave rectifier circuit of FIG. 2, thus giving a repetition frequency of the order of 120 cycles per second for the usual 60 cycle house current.

A still further alternate embodiment for the electrical means employs only alternating current. This is shown in FIG. 7. This simple circuit employs a low voltage secondary 48, which may be the same as secondary 14 of FIG. 2. The terminals of the secondary winding connect directly to the x points of the electrical supply means of FIG. 7. Transformer 49 may be of the same general nature as transformer -11 of FIG. 2.

In all of the foregoing arrangements of electrodes and electrical means to excite the electrodes, the object is to induce a continuous muscular contraction, which condition is defined by the physiological term tetany. This is not the same condition as is desired for therapy, where pulses of electrical energy are normally sufiiciently spaced in time to allow relaxation of the muscle between pulses; thus to repeatedly exercise the muscle.

To accomplish tetany a pulse repetition frequency of the order of cycles is preferable. Frequencies higher than this will also accomplish tetany, as up to 100,000 cycles per second, after which higher frequencies donot produce muscular contraction. The objects of this invention may be accomplished at a frequency lower than that which accomplishes tetany, such as down to 30 cycles per second. At the lower frequencies, even if relaxation of the arrector pili muscles occurs, to a degree the relaxation is brief with respect to the time required for shaving a given area and so the hair-erection effect is quite fiully accomplished, particularly should the operator go over a given area more than once. It is seen that the frequencies of 60 and cycles per second, obtain able from the usual household current, are suitable.

While the 2 to 5 volt range for the excitation voltage previously defined is considered suitable and a fixed voltage may be chosen for a given razor to handle usual shaving needs, a potentiometer may be included in any of the circuit embodiments and the maximum voltage raised so that a range of from 1 to 10 volts is available to accommodate skins of various conductivities and the sensitive skins of youths and women, or the insensitive skins of outdoor men. It will be recognized that these voltages, under 20 volts, are low voltages.

It will be understood that the exact configuration of individual electrodes may be varied and the spaced relation between the activating electrode and the return electrode. The requirement is that the current density be sufficient to stimulate the arrector pili just prior to shaving. When the path between the activating and the re turn electrodes is long the exciting voltage should be high, and vice versa; i.e., high for FIG. 5 and low for FIG. 1.

If desired, a solution to increase the conductivity of the skin may be applied prior to shaving. This may take the form of a saline solution, or even impure water, along with other pleasing ingredients in a preshave lotion. By impure water is meant water other than distilled water; i.e., water having ion electric charge carriers. Proper shaving results may be obtained, however, without a lotion. A higher voltage is employed.

In addition to the illustrative structural and circuit embodiments previously described, other embodiments are possible. For instance, in place of buzzer device 21. a vibrator of the type employed forvacuum tube auto radios may be used, as may one employing a tuning fork to give a particular frequency above the usual power line frequencies. I

The arrector pili muscle is also termed the arrectores pilorum muscle.

The device according to this invention operates as follows. The electrical circuit of FIGS. 2, 3, or 6, etc. is placed in operation, along with the mechanical clipper constituting the shaver per se. The person shaving then moves the device over the area to be shaved in the usual way. This causes current pulses to fiow from the electrical circuit through rollers (electrodes) 4-7 in the example of FIG. 1 and into the flesh of the area being shaved. This activates the arrector pili muscles, which are attached individually to each hair of a human being, causing each hair to erect perpendicular to the skin. The motion of the device over the area to be shaved causes each hair to be cut off by the mechanical clipper close to the skin. The device then leaves the shaved area, upon the continuation of the known process of shaving, and the arrector pili muscles relax.

Although this invention has been described in preferred forms with a certain degree of particularity, this has been only by way of example. Various changes in the details of construction and of circuit arrangement may be made Without departing from the spirit and scope of the invention as claimed below.

Having thus fully described the invention and the manner in which it is to be practiced, I claim:

1. An electric shaver comprising;

(a) means for cutting hair,

(b) an activating electrode disposed adjacent to and electrically insulated from said means for cutting hair,

to activate the arrector pili muscle of each hair about to be cut by said means for cutting hair,

(c) a return electrode upon said electric shaver and disposed away from said activating electrode, and

(d) pulsating low voltage electrical means connected between said activating electrode and said return electrode to electrically activate said electrodes for erecting each hair by electrical stimulation of only the arrector pili muscle of each hair,

thereby obtaining a close shave.

2. The electric shaver of claim 1, in which (a) said return electrode is disposed upon said shaver farther away from said means for cutting hair than is said activating electrode.

3. The electric shaver of claim 1 in which said electrical means comprises;

(a) a source of alternating current, and

(b) only half-wave means to rectify said alternating current connected in series with said source.

4. The electric shaver of claim 1 in which;

(a) said electrical means is constituted to produce voltage pulses, and

(b) said electrical means is connected to impress negative voltage pulses upon said activating electrode.

5. The electric shaver of claim 1 in which;

(a) said electrical means produces voltage pulses having a repetition frequency in the range of from thirty to several hundred cycles per second.

6. The electric shaver of claim 1 in which said electrical means comprises;

(a) a source of alternating current, and

(b) only full-wave means to rectify said alternating current connected to said source.

7. The electric shaver of claim 1 in which said electrical means comprises;

(a) a battery,

(b) electromechanical means to interrupt current flow from said battery connected in series with said battery, and (c) a conductive impedance having a value low with respect to the impedance of flesh,

said conductive impedance connected in shunt to said battery and said electromechanical means between said activating electrode and said return electrode to provide sumcient flow of current from said battery to energize said electromechanical means.

8. The electric shaver of claim 1 in which;

(a) said electric means is constituted to produce alter nating current voltage pulses.

9. The electric shaver of claim 1 in which;

(a) the area of said activating electrode that contacts the skin of the area being shaved is less than the area of said return electrode that also contacts an adjacent area of the same said SKln.

References Cited by the Examiner UNITED STATES PATENTS 1,291,318 l/l9l9 White l284l0 2,867,()39 l/l959 Zach 30-34 3,197,612 7/1965 Reich 30-34 X 3,230,423 1/ 1966 Fredrickson 3174 WILLIAM FELDMAN, Primary Examiner. MYRON C. KRUSE, Examiner. 

1. AN ELECTRIC SHAVER COMPRISING; (A) MEANS FOR CUTTING HAIR, (B) AN ACTIVATING ELECTRODE DISPOSED ADJACENT TO AND ELECTRICALLY INSULATED FROM SAID MEANS FOR CUTTING HAIR, TO ACTIVATE THE ARRECTOR PILI MUSCLE OF EACH HAIR ABOUT TO BE CUT BY SAID MEANS FOR CUTTING HAIR, (C) A RETURN ELECTRODE UPON SAID ELECTRIC SHAVER AND DISPOSED AWAY FROM SAID ACTIVATING ELECTRODE, AND 